/* Copyright (C) 2004 - 2006  db4objects Inc.  http://www.db4o.com

This file is part of the db4o open source object database.

db4o is free software; you can redistribute it and/or modify it under
the terms of version 2 of the GNU General Public License as published
by the Free Software Foundation and as clarified by db4objects' GPL 
interpretation policy, available at
http://www.db4o.com/about/company/legalpolicies/gplinterpretation/
Alternatively you can write to db4objects, Inc., 1900 S Norfolk Street,
Suite 350, San Mateo, CA 94403, USA.

db4o is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
for more details.

You should have received a copy of the GNU General Public License along
with this program; if not, write to the Free Software Foundation, Inc.,
59 Temple Place - Suite 330, Boston, MA  02111-1307, USA. */
namespace Db4objects.Db4o.Foundation
{
	/// <exclude></exclude>
	public class TimeStampIdGenerator
	{
		private long _last;

		public static long IdToMilliseconds(long id)
		{
			return id >> 15;
		}

		public TimeStampIdGenerator() : this(0)
		{
		}

		public TimeStampIdGenerator(long minimumNext)
		{
			_last = minimumNext;
		}

		public virtual long Generate()
		{
			long t = Sharpen.Runtime.CurrentTimeMillis();
			t = t << 15;
			if (t <= _last)
			{
				_last++;
			}
			else
			{
				_last = t;
			}
			return _last;
		}

		public virtual long Last()
		{
			return _last;
		}

		public virtual bool SetMinimumNext(long newMinimum)
		{
			if (newMinimum <= _last)
			{
				return false;
			}
			_last = newMinimum;
			return true;
		}
	}
}
